If your server operates in a Windows domain environment and you wish to support single sign on and delegation of credentials from one machine to another then you need The SSPI Negotiate Option Pack. With this set of code you can add support for Kerberos and NTLM authentication and security via the Negotiate SSPI interface.
The SSPI Negotiate Option Pack can be easily added to your server after you’ve developed all of your business logic as the interface slides in between the data coming off of the wire and the point where The Server Framework gives you the data to work with, you simply change a base class and your connections can be secured and authenticated.
Whilst you could do this integration yourself, the SSPI API that you need to master is complex and so there’s quite a bit of work to do to integrate it cleanly with the asynchronous sockets and overlapped I/O that The Server Framework uses. With The SSPI Negotiate Option Pack we’ve done this work for you, so you can simply update your project and add secure, authenticated connections to your servers or clients in minutes.
See here for example servers.
See here for documentation.